قال رسول الله (صلي الله عليه وسلم : ""ثلاث من كن فيه وجد حلاوة الإيمان : من كان الله ورسوله أحب إليه مما سواهما ، ومن أحب عبدا لا يحبه إلا لله ، ومن يكره أن يعود في الكفر ، بعد إذ أنقذه الله ، كما يكره أن يلقى في النار ."" الراوي: أنس بن مالك المحدث: البخاري - المصدر: صحيح البخاري - الصفحة أو الرقم: 21 خلاصة الدرجة: [صحيح]
The Prophet said, "Whoever possesses the following three qualities will taste the sweetness of faith. (1) The one to whom Allah and His Apostle become dearer than anything else.(2 )Who loves a person and he loves him only for Allah's sake . (3 )Who hates to revert to disbelief (Atheism) after Allah has brought (saved) him out from it, as he hates to be thrown in fire (Sahih Al Bukhari Volume 1, Book 2, Number 20)
Commentary :
1) Praise be to Allah who guided us to the straight way.Praise be to Allah who picked us up from the darkness of ignorance,atheism,polytheism and blasphemy to the light of faith, oneness and monotheism.
ۖ "وَقَالُوا الْحَمْدُ لِلَّهِ الَّذِي هَدَانَا لِهَٰذَا وَمَا كُنَّا لِنَهْتَدِيَ لَوْلَا أَنْ هَدَانَا اللَّهُ ۖلَقَدْ جَاءَتْ رُسُلُ رَبِّنَا بِالْحَق"
'' The praise to Allah, 'Who hath guided us to this. We could not truly have been led aright if Allah had not guided us. Verily the messengers of our Lord did bring the Truth." (7/43 )
ِسْمِ اللَّهِ الرَّحْمَٰنِ الرَّحِيم"" الْحَمْدُ لِلَّهِ رَبِّ الْعَالَمِين" ِ الرَّحْمَٰنِ الرَّحِيم" مَالِكِ يَوْمِ الدِّين" إِيَّاكَ نَعْبُدُ وَإِيَّاكَ نَسْتَعِين" اهْدِنَا الصِّرَاطَ " الْمُسْتَقِيمَ" " صِرَاطَ الَّذِينَ أَنْعَمْتَ عَلَيْهِمْ غَيْرِ الْمَغْضُوبِ عَلَيْهِمْ وَلَا الضَّالِّينَ" . "
" In the name of Allah, the Beneficent, the Merciful. (1) Praise be to Allah, Lord of the Worlds, (2)The Beneficent, the Merciful. (3) Master of the Day of Judgment,(4) Thee (alone) we worship; Thee (alone) we ask for help.(5) Show us the straight path,(6) The path of those whom Thou hast favoured; Not the (path) of those who earn Thine anger nor of those who go astray. (7) (1/1-7) .

2) In fact the faith of the only true God (pbth) is our true fortune in this life .Living in the side of Allah is the biggest grace .If He (pbth) approaches you to him,you will feel full inner peace and the true happiness,you will taste the sweetness of faith.If He fill your heart with a ray of faith you will feel as if you owned all that world.He is Allah the Lord of that world.He created us in the best image . He (pbth) He deserves all our love , all our gratefulness . It is said that the human nature always loves those who do good to her.If we think how much Allah gave us and still.If we read that open book what would we say? That vast sky,the sun,the moon,the mountains,the rain,the rivers,the seas.the plants.If we meditated our bodied ,our eyes,our ears, our hands .Allah says in the Quran :
"هَذَا خَلْقُ اللَّهِ فَأَرُونِي مَاذَا خَلَقَ الَّذِينَ مِن دُونِهِ بَلِ الظَّالِمُونَ فِي ضَلَالٍ مُّبِينٍ"
"Such is the Creation of Allah: now show Me what is there that others besides Him have created: nay, but the Transgressors are in manifest error" (31/11)

3) Then If we wanted to taste the sweetness of Faith firstly we must love Allah (pbth) more than anything else and also love his messenger Muhammad (pbuh) who Allah chose to reach us his final message Islam and his final book (the Quran ) He was honest and told us what Allah ordered him by The angel Gabriel .He was the model of obedience and submission to Allah .He didn't leave anything good till he invited us to do it and he didn't leave anything bad till he warned us from doing it. We must love Allah and his messenger more than ourselves or our relatives,more than our parents,our children,more than fortunes to taste the sweetness of faith.
4) Secondly,The love of the slaves of Allah .The messenger teaches us the true love that must be in Allah or for Allah not for any other purposes.
5) Thirdly if a person was keen on his faith and stick to it strongly and does what Allah ordered him to do and avoids doing what angers Allah.He hates atheism,polytheism and blasphemy because they lead to hell.
6) Every one who owns the three qualities will (God willing) enjoy tasting the sweetness of faith . I hope that Allah grant us all that.